I've done this sort of upgrade with many of my other projects without issues, but this time around I got stumped on the following error:
MappingException: Missing type or column for columnThe error message was not particularly helpful, since I know the domain class mapping was correct in a previous version of Grails. The way associations between domain classes, hasn't changed. So find the underlying cause wasn't easy and I wanted to share it with you in case you run into a similar problem.
In my domain classes there many getters methods that had no corresponding field defined. For example, I had a getter called, getFoo() but there was no corresponding field in the domain class called 'foo'. When using such getter methods in Grails, normally we should define a static list of transients as follows:
static transients = ['foo']
Once these transients were defined, then the error messages stopped